I found the problem in dir(). There is no enumeration to check the types and remove the key . I'm not a Java guru (I'm having to do some refresher reading, so I'm attempting a solution that will call _setattr_ to remove the key, if it matches 'attribute deleted' && !interactive. Exactly where to put it is the hard part for me. I'm still working on it. Is it acceptable to create a new function, like public void respectAttributeDeleted()?